In the case of mobile inhabitable units, such as ships, mobile homes and caravans, mobile drinking water installations are also provided. They have a water tank, which is filled at a stationary water source and then, during the movement of the unit and independently of stationary water sources, is available for drinking water supply purposes. For stabilizing the drinking water quality and in particular to avoid bacteria, it is known to add silver ions to the water. It is also-appropriate to filter the water supplied to the mobile tank, in order to remove pollutants before the water enters the tank.
It has now been found that such a filter with the residual water therein can be highly contaminated, even if silver ions are added to the water in the water tank. On refilling, said highly contaminated water is rinsed out of the filter into the water tank and cannot be restored to a satisfactory state even when provided with silver ions. It has in particular an extremely unpleasant smell. This deficiency has also not been eliminatable by an additional activated carbon filter. However, it is not recommended to carry out silver ion admixing prior to flowing through the filter, because to a significant extent the silver ions are filtered out in the filter and therefore greatly reduce the effectiveness of silver ion admixing with respect to the silver ions contained in the water in the tank, i.e. the efficiency of silver ion admixing is reduced.
Thus, whilst ensuring a high efficiency of silver ion admixing in a mobile drinking water supply installation, the problem of the invention is to prevent contamination of the water still in the supply pipe to the water tank and more particularly also in the filter.